The use of nitrous oxide injection into racing and high performance engines is well known. For example, a U.S. Pat. No. 4,683,843 of Narcia et al. discloses a nitrous oxide fuel injection system for high performance vehicles. The system injects a supply of liquid nitrous oxide to a vehicle engine to provide a sudden burst of power.
The amount of nitrous oxide which is dispensed from a pressurized container during a given time is limited by the capacity and the pressure under which the gas is stored. Therefore, heating the pressurized container or bottle will conduct heat to the nitrous oxide to expand the nitrous oxide and increase the pressure within the container. This allows greater amounts of nitrous oxide to be injected into an engine. For this reason, auto racers such as drag racers often heat the nitrous oxide storage container prior to placing the container into a motor vehicle.
Some methods for heating pressurized containers include holding the flame of a torch in direct contact with the pressurized container and wrapping the container with tape and placing the wrapped container in sunlight which may cause the container to explode. It is also known to apply fitted nylon insulated blankets and a thermostatically controlled 12 VDC heating element to nitrous oxide pressurized storage bottles.
A further approach for heating a pressurized container is disclosed in the U.S. Pat. No. 6,433,316 of Sigety et al. As disclosed therein, a heater assembly includes a container holding portion and a heater housing portion which are separated by a divider and a baffle. At least one aperture and one selectable movable member which substantially covers the aperture when the movable member is in a closed position are provided. When in an open position, the movable member couples with the baffle to form a heating passage to indirectly heat the container.
There is one problem with current methods of heating pressurized nitrous oxide containers. The problem is that such methods are ineffective during extreme temperature variations as for example when the ambient air temperature exceeds 86° F. which is the preferred temperature for which such systems are designed. This optimum desired temperature and subsequent bottle resultant pressure of 900 to 950 psi is needed for the proper consistent operation of the nitrous oxide injection system. Such temperature and pressure are needed in spite of temperature extremes such as temperatures as high as 135° F. inside a vehicle during a hot summer day.
As a result of extreme temperature conditions conventional nitrous oxide systems suffer from large swings in applied power and performance swings in a vehicle's engine. Such performance swings are unacceptable in most racing venues. A further problem associated with such systems is that under extreme conditions, the nitrous oxide bottle temperature may increase to thereby increase the pressure in the bottle beyond the allowable pressure which may cause serious engine damage. A still further problem with current heaters is the excess amount of energy to operate a heating element. For example, such systems may draw between 20 and 35 DC amps in their heating mode. This puts an excessive load on a battery and charging system. Further, the heating element may reach temperatures of 400° F. which will cause serious burns if touched.
Thermo-electric environmental chambers are also known. For example, a portable thermo-electric cooling and heating food appliance is disclosed in the U.S. Pat. No. 4,823,554 of Trachtenberg et al. As disclosed therein, a base unit is provided which can be connected to the cigarette lighter receptacle of a vehicle. The use of a Peltier element and a selective cool or heat control circuit cool or heat the appliance and the foods or liquids contained therein. Such chambers are effective for maintaining food and/or drink at a selected temperature and for maintaining such foods at the chosen temperature after disconnecting the power. However, such systems have not heretofore been applicable for controlling the temperature and pressure of a nitrous oxide pressurized bottle.
It is presently believed that there is a need and a potential commercial market for an improved temperature control system in accordance with the present invention. It is believed that there is a need for such systems that will overcome many of the short comings of the prior art. For example, such systems provide protection and control of nitrous oxide pressurized storage bottles to provide optimum stabilized bottle temperature and pressure for consistent performance regardless of extreme variations in ambient temperature.
Advantages in accordance with the present invention include its ease of installation in a vehicle and a reduced requirement for a high DC current draw from a vehicle battery/charging system in order to operate both heating and cooling functions. In addition, the system uses a Peltier junction thermoelectric heat pump for heating and cooling.
The system in accordance with the present invention also provides a thermostatic temperature control system that can be set to a preferred operating temperature and operate automatically to maintain the operating temperature even during extreme ambient temperatures. Such systems also provide reasonably safe operating temperatures and in a preferred embodiment of the invention provide real time bottle temperature by means of a highly accurate digital temperature gauge.
Other objects and advantages of the present invention will become clear from the following description.